Animal Vision

Not all animals see the world as humans do. For many animals the world is seen in blurry, faded grey, and pale clours. Also some animals can see in total darkness, or even see colours that are beyond the human colour spectrum.

All the different animals in the world see in a variety of different ways. To get a vast variety of individuality throughout the animal kingdom, I will study dogs, cats, snakes, horses, insects, shrimp, crabs, and birds.

Dogs and Cats

Many humans beleive and accept that dogs and cats are completely colour blind, and can only see shades of white, grey and black. The truth is dogs and cats can see pale, washed out colours whcih is similar to a human who is red and green colour blind. However, dogs and cats may see minimal colour but have better peripherals and ability to see in the dark.

Figure 1
dogvis.jpg

Snake vision
Snakes are an animal which really do have two eyes. Snakes use their normal eyes during the day to see light and a few different colours, while at night they switch over to see in the dark. Snakes have a pit organ which can pick up infared heat signals, to detect warm objects.
external image images?q=tbn:ANd9GcTzLSR1jLVJt4ap3EhEmoBmi0mBam7eewJmYX57XZH4NL5aFoKpxooT3RWCqA
Horse Vision
Horses and similar animals such as zebras have eyes located on the sides of their head, giving them a very large peripheral vision. Having a large peripheral vision, aids these type of animals to escape predators and survive. Although they may be able to escape predators, their eye sight has some large drawbacks including: a blind spot in the center of their sight and, lack of binocular vision which means their vision is split into two and does not join in the middle. Horses also have abilities to see in the dark, and have minimal colour in their sight since they mostly see in shades of grey.
external image images?q=tbn:ANd9GcQ4R939P9ei5cqAvBeLBkBSGz5FEmDkrrKyoiVSWW1DWov2aVQn
Insects
Most insects use compound eyes, made up of thousands of lens in a honeycomb pattern. Each lens can see a tiny section of an image, and when put together, the insect can see the image as a whole picture. Insects are vastly different, since many insects such as butterflies can see many more colours than the human eye, while other insects can not see nearly as many colours as humans.


external image 4849082094_66d7fd82af_z.jpg
Shrimp and Crab
Shrimp and crab have the least developed vision known to man. Shrimp and crab have compund eyes similar to insects but do not see detail. They use other sense to detect predetors other than vision, since a predator and plant would look the same.

Bird Vision
Birds have a greater range of vision than humans, and can see many more colours including ultraviolet light. Many birds such as eagles and vultures have outstanding binocular vision, enabling them to spot prey from thousands of feet away.
external image eagle.jpg

Animal Vison relates to optics, since it shows how different animals refract and see light differently compared to humans. Mamy animals see different since they have fewer or more rods and cones than humans which gives the difference in vision.

Josh
References

http://www.eyes-and-vision.com/how-animals-see-the-world.html

http://webecoist.momtastic.com/2009/01/14/animal-vision-color-detection-and-color-blindness/